A light fixture has been known in the art which lights a semiconductor light-emitting element (light source) by supplying a constant direct current from a power supply circuit to a light-emitting module. For example, according to Japanese Unexamined Patent Application Publication No. 2012-9772, a power supply circuit and a semiconductor light-emitting element are housed in a single light fixture, and the power supply circuit outputs a current with a trapezoidal waveform, thereby lighting the semiconductor light-emitting element.
When located distant from each other, a power supply circuit and a light source are connected together via an electric wire. In that case, however, contact failure occurring at a connection point of any electric wire could generate arc discharge at the connection point. Particularly when direct current (DC) power is supplied from the power supply circuit to the light source, the arc discharge tends to continue for a significant amount of time.